Assessment of Serum Cytokine Concentrations in Infective Endocarditis Patients

Abstract

Introduction: Infective Endocarditis (IE) remains a devastating disease despite advances in diagnosis and treatment. The main stay of diagnosis is blood culture, however many cases are culture negative. Measuring levels of inflammatory markers in serum of these patients will aid in the diagnosis. Aim: To estimate the levels of various cytokines in the serum samples of IE patients and to compare them with two control groups- healthy individuals and patients with non-IE infections. Materials and Methods: Serum concentration of Interleukin (IL)- 1β, IL-6, IL-8, IL-10, IL-12, Tumour Necrosis Factor (TNF)-α and Interferon (IFN)-γ of 52 IE patients, 10 patients with non-IE infections and 10 healthy individuals were determined, between February 2017 and June 2018, using quantitative Enzyme Linked Immuno Sorbent Assay (ELISA). Comparison of cytokine values among the groups was done using Kruskal Wallis test, post-hoc test and ROC curve. Results: IE patients presented with high serum concentration of IFN-γ, TNF-α, IL-1β, IL-6 and IL-8 when compared to control groups. ROC curve analysis comparing IE patients with non-IE patients suggested that IL-6 (AUC-0.8) and IL-8 (AUC-0.876) may serve as reliable markers for the diagnosis of IE. Conclusion: Measurement of various serum cytokines showed that the levels of all of them except IL-10 and IL-12 were significantly higher in patients with IE and non-IE infections as compared to healthy controls. IL-6 and IL-8 levels may serve as additional biomarkers in the diagnosis of IE.

Keywords

• biomarkers
• endocardium
• enzyme linked immunosorbent assay
• infection